1/5 scale Gee Bee Model D (From foam to balsa)

cyclone3350

Master member
Moving away from electrics for a while. My next big project is probably too big a step without an intermediate step in between, So, I've decided to try this one first & hopefully will be quick & not too painful of a learning curve. I made the original one out of 2mm depron using this website: https://www.rcgroups.com/forums/showthread.php?290818-Electric-Orange-Gee-Bee-D-Park-Racer The original version is 36" & I made this 1s'er reduced to 20". The plan is to use ply and balsa for the fuse, balsa sheet a hot wire pink foam wing & I will figure out what to do for the tailfeathers later. I have this Magnum XL 91FSR that desperately needs a home. I will use a Morris Mini Motors CDI conversion & see if it will run on gas. If not, the CDI will do well for nitro. Shrunk the plans down to 50% too make it into individual pages and then scanned them and reprinted them @ Kinko's @ 340%. Now it is off to the jig and band saw.
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OliverW

Legendary member
Yeah true. I've been looking at doing a golden age build for a long time, just have had no time for building lately. If I were to though I'd get a big ol gee bee z and buy a moki radial for it lol. But yeah I see what you're saying. Did a big electric setup and wasn't a huge fan. Even for small stuff I've been preferring glow. Just fuel up, tap the spinner with the starter, and it fires right up!
 

cyclone3350

Master member
Yeah true. I've been looking at doing a golden age build for a long time, just have had no time for building lately. If I were to though I'd get a big ol gee bee z and buy a moki radial for it lol. But yeah I see what you're saying. Did a big electric setup and wasn't a huge fan. Even for small stuff I've been preferring glow. Just fuel up, tap the spinner with the starter, and it fires right up!

That's funny U mentioned it. My dream bird is a Moki 7 banger on a 1/3rd Pup.
 

cyclone3350

Master member
Yep. Easily if the plane has some mild balsa reinforcements, along with some ply around the firewall area. Me and @BlockerAviation have both done it with his attempts being more successful as mine was a nutball 😂

Looking @ your stuff & seeing what an amazing job @BlockerAviation did with his Cub, is what gave me the idea. For this size, my fuse is going to be all ply formers and balsa sheeting.
 

BlockerAviation

Legendary member
Looking @ your stuff & seeing what an amazing job @BlockerAviation did with his Cub, is what gave me the idea. For this size, my fuse is going to be all ply formers and balsa sheeting.
Thanks man, that means a lot to here that. I have a feeling that the geebee will be awesome in the air and a really good conversation piece. At least my cub is, you should see the look I get when I say it's foam board 😂
 

cyclone3350

Master member
OMG! 3 days of work and pieces of carboard is all I have to show!

This is after doing some measurements & realizing that the original plans were too narrow. Also, the weight of a fully sheeted balsa fuse and solid balsa tail for the wing area was also an issue. I finally settled down on the original plan, widened for the front of the fuse, sheeted, and the rear built up portion of a Haffke set of plans. The tail will also be built out of 3/16 balsa sticks. After days of plotting points of contact and drawing things out on the drafting board, I finally came up with some parts patterns. Did some dry fitting to see how everything lines up before I star cutting. I still have the cockpit hatch to go and some 1/16 birch ply doublers to go behind the 1/4 ply firewall. The rest of the formers and servo / receiver tray will be 1/8th lite ply, & the last 2 formers will be 1/8th balsa. I am still sticking to a foam core set of wings. God, I hope to have this fuse framed up by tonight. BTW, to make this 1/5, the WS will be 60" & the length is 41.5"
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cyclone3350

Master member
I had to be out of town for the past week. Now that I am back, I definitely put the scroll saw to good use. All the cardboard patterns R now plywood and put together. Got the rear section framed up & ready to join the front section. If U take clothes pins & turn them inside out, they make for good mini clamps.
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cyclone3350

Master member
Finished framing up the the rear fuse section. I did this part in 2 halves & glued them together. The pans had only 2 former for this. I thought this to be insufficient, but figured that if that if this is deigned this way, then it should work. Maybe, if covering with something low shrink like silkspan. I plan on using one of my last rolls of Solatex & that stuff would shrink hour glass shapes into the fuse for sure. So how do I add extra formers into something already frame up? Building rectangles with balsa strips & adding cross stringers to attach to the side stringers. Once glued, sawed out the center sections & it worked. Took some time unfortunately. Going back at it tonight. I think I will hot wire the wings. Hmmm, maybe too tired for that & should just do the tail feathers.
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FlyingTyger

Elite member
If you don't already plan to, I would add a ply gusset at the rear of the wing saddle. Otherwise I see that as a weak point that may cause problems over time.
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cyclone3350

Master member
If you don't already plan to, I would add a ply gusset at the rear of the wing saddle. Otherwise I see that as a weak point that may cause problems over time.
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That section is going to be a 1/8th balsa doubler followed by 1/16th balsa sheeting. I am waiting for the wing to be done so I can make an exact cut out for the saddle.This is the mock up with the sheeting pattern made. A 1/8th lite ply gusset behind the doubler would be an added strength without adding much to the weight.
 

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Flightspeed

Convicted Necroposter
ok, I saw four strokes mentioned. How do y’all start them things! My starter won’t touch em! Chicken stick don’t really work for first time starting a engine. I’ll stick with two stroke as much as possible. Thanks to miserable 4 stroke I have a plane I can’t fly lol.
 

FlyingTyger

Elite member
ok, I saw four strokes mentioned. How do y’all start them things! My starter won’t touch em! Chicken stick don’t really work for first time starting a engine. I’ll stick with two stroke as much as possible. Thanks to miserable 4 stroke I have a plane I can’t fly lol.

What size?
 

FlyingTyger

Elite member
That section is going to be a 1/8th balsa doubler followed by 1/16th balsa sheeting. I am waiting for the wing to be done so I can make an exact cut out for the saddle.This is the mock up with the sheeting pattern made. A 1/8th lite ply gusset behind the doubler would be an added strength without adding much to the weight.

Perfect. For some reason I thought you were using foamboard for the forward solid area.
 

cyclone3350

Master member
ok, I saw four strokes mentioned. How do y’all start them things! My starter won’t touch em! Chicken stick don’t really work for first time starting a engine. I’ll stick with two stroke as much as possible. Thanks to miserable 4 stroke I have a plane I can’t fly lol.

I am about to find out. This one was given to me, so I used that rational to justify the additional expense & ordered an RCEXL ignition system for it.:unsure: Hope it works.